KR20050018728A - Motion vector derivation method, moving picture coding method, and moving picture decoding method - Google Patents

Abstract

The motion vector derivation unit 11 compares whether or not the parameter TR1 related to the reference vector exceeds a predetermined value, and the parameter stored in advance according to the comparison result of the comparison unit 20 and the comparison unit 20. Switching section 21 for switching between selecting the maximum value of TR or selecting parameter TR1, multiplier parameter table (for multipliers) 22, and parameter TR1 and the reciprocal of this parameter TR1 (1) Multiplier parameter table (for dividing) 24 corresponding to the value approximated by "

Description

Motion vector derivation method, moving picture coding method, and moving picture decoding method {MOTION VECTOR DERIVATION METHOD, MOVING PICTURE CODING METHOD, AND MOVING PICTURE DECODING METHOD}

The present invention provides a motion vector derivation method for deriving a motion vector representing a motion in a block unit between images, a moving picture encoding method for encoding a moving picture by inter-picture prediction encoding with motion compensation using the derived motion vector, and a moving picture. It relates to a decoding method.

In recent years, with the development of multimedia applications, it has become common to deal with all media information such as images, audio, text, and the like. At this time, by digitizing all media, it becomes possible to handle media uniformly. However, since digitalized images have a huge amount of data, information compression techniques of images are indispensable for accumulation and transfer. On the other hand, in order to interoperate compressed image data, standardization of compression techniques is also important. Standard standards for image compression technology include H.261, H.263 of the International Telecommunication Union Telecommunication Standardization Division (ITU-T), Moving Picture Experts Group (MPEG) -1 and MPEG- of the International Organization for Standardization (ISO). 2, MPEG-4 and the like.

As a technique common to these moving picture coding methods, there is inter picture prediction with motion compensation. In the motion compensation of these moving picture coding methods, each picture constituting the input image is divided into a rectangle of a predetermined size (hereinafter referred to as a block), and prediction is referred to by encoding and decoding from a motion vector representing inter picture motion for each block. Create an image.

The motion vector is detected for each block or for each divided area. For a picture to be encoded, a reference picture is a coded picture that is located forward or backward (hereinafter, simply referred to as front and rear) according to the display order of the image. In motion detection, a block (region) that can most appropriately predict a block to be encoded is selected from the reference pictures, and the relative position of the block with respect to the block to be encoded is an optimal motion vector. At the same time, a prediction mode that is information specifying a prediction method that can be most appropriately predicted from the referenceable pictures is determined.

As a prediction mode, for example, there is a direct mode in which inter picture prediction encoding is performed by referring to a picture that is forward or backward in display time (for example, ISO / IEC MPEG and ITU-T VCEG Working Draft Number 2, Revision). 22002-03-15 P.64 7.4.2 Motion vectors in direct mode). In the direct mode, the motion vector is not explicitly encoded as encoded data, but is derived from the already encoded motion vector. That is, by referring to a motion vector of a block of a picture to be encoded and a block (hereinafter referred to as a reference block) at the same coordinate position (spatial position) within the picture within a coded picture in the vicinity of the picture to be encoded, The motion vector of the block to be encoded is calculated. Then, a predictive image (motion compensation data) is generated based on this calculated motion vector. In the case of decoding, the motion vector of the direct mode is derived from the motion vectors which have been similarly and already decoded.

Here, the calculation of the motion vector in direct mode is demonstrated concretely. 1 is an explanatory diagram of a motion vector in the direct mode. In Fig. 1, the picture 1200, the picture 1201, the picture 1202, and the picture 1203 are arranged in the display order. The picture 1202 is a picture to be encoded, and the block MB1 is a block to be encoded. In FIG. 1, a case where multiple inter prediction is performed on a block MB1 of a picture 1202 is performed by using a picture 1200 and a picture 1203 as a reference picture. In the following description, for the sake of simplicity, the picture 1203 is described as the rear of the picture 1202 and the picture 1200 as the front of the picture 1202. However, the picture 1203 and the picture 1200 are always in this order. It does not have to be listed.

The picture 1203, which is a reference picture behind the picture 1202, has a motion vector that refers to the picture 1200 in front. Therefore, the motion vector of the encoding target block MB1 is determined using the motion vector MV1 included in the reference block MB2 of the picture 1203 positioned behind the encoding target picture 1202. The two motion vectors MVf and MVb obtained are calculated using the following equations (a) and (b).

MVf = MV1 x TRf / TR1... Equation 1 (a)

MVb = -MV1 x TRb / TR1... Equation 1 (b)

Here, MVf is a forward motion vector of the encoding target block MB1, MVb is a backward motion vector of the encoding target block MB1, and TR1 is a time interval between the picture 1200 and the picture 1203. (Time interval to the reference picture of the motion vector MV1), TRf is the time interval between the picture 1200 and the picture 1202 (Time interval to the reference picture of the motion vector MVf), and TRb is the picture ( 1202) and the time interval between the picture 1203 (time interval up to the reference picture of the motion vector MVb). In addition, TR1, TRf, and TRb are not limited to the time interval between pictures, for example, the difference between the data using the difference in picture numbers allocated to each picture and the display order (or information indicating the display order of pictures) of the pictures. Temporal intervals in the display order between the pictures, such as data using the data and data using the number of pictures, and are used as indicators used in the scaling of motion vectors (either explicitly or implicitly included in the stream). Data or data associated with a stream).

Next, a flow of processing for obtaining a motion vector will be described. 2 is a flowchart showing the flow of processing to find a motion vector. First, information on the motion vector of the reference block MB2 is obtained (step S1301). In the example of FIG. 1, the information of the motion vector MV1 is acquired. Next, a parameter for deriving the motion vector of the encoding target block MB1 is obtained (step S1302). The parameter for deriving the motion vector of the encoding target block MB1 is scaling coefficient data used when scaling the motion vector acquired in step S1301. Specifically, TR1, TRf, and TRb in Formula 1 (a) and Formula 1 (b) correspond. Subsequently, these parameters are used to multiply using equations (1) and (1), and the motion vector obtained in step S1301 is scaled to move the encoding target block MB1. The vectors MVf and MVb are derived (step S1303).

As shown in Equations 1 (a) and 1 (b), a division process is required to derive a motion vector. However, as a first subject, the division process takes a lot of time for the calculation process as compared with the calculation of addition or multiplication. This is not preferable in view of the fact that a low power consumption specification device is used for a device that requires low power consumption such as a mobile phone.

Therefore, in order to avoid the division process, it is conceivable to derive the motion vector by the multiplication process with reference to the multiplier parameter corresponding to the divisor. As a result, the calculation can be performed by multiplication with less calculation amount instead of division, and the calculation of scaling can be simplified.

However, as a parameter for deriving the motion vector as the second task, various values are applied depending on the distance between the reference picture and the picture of the target block, and thus, the parameter can take many values. In other words, if a multiplier parameter corresponding to all divisors is prepared, a large number of parameters must be prepared, which requires a lot of memory.

Therefore, in order to solve the said 1st subject and the 2nd subject, an object of this invention is to provide the motion vector derivation method, the moving image coding method, and the moving image decoding method which derive a motion vector with little calculation amount.

1 is an explanatory diagram of a motion vector;

2 is a flowchart showing a flow of a process for obtaining a conventional motion vector;

3 is a block diagram showing the structure of a video encoding apparatus of the present invention;

4 is a block diagram showing the configuration of a motion vector derivation unit according to the present invention;

5 is a diagram showing a multiplier parameter table of the present invention;

6 is a flowchart illustrating a method of deriving a motion vector of the present invention;

7 is an explanatory diagram of a motion vector of the present invention;

8 is a block diagram showing the configuration of a motion vector derivation unit according to the present invention;

9 is a flowchart illustrating a method of deriving a motion vector of the present invention;

10 is an explanatory diagram of a motion vector of the present invention;

11 is an explanatory diagram of a motion vector of the present invention;

12 is a block diagram showing the configuration of a motion vector derivation unit according to the present invention;

13 is a block diagram showing the structure of a moving picture decoding apparatus of the present invention;

FIG. 14 is an explanatory diagram of a recording medium for storing a program for realizing the moving picture coding method and the moving picture decoding method of each embodiment by a computer system, and (a) an example of a physical format of a flexible disk as a main body of a recording medium. An explanatory diagram showing the appearance of a flexible disk, (b) an appearance, a cross-sectional structure, and a flexible disk as viewed from the front of the flexible disk, and (c) a configuration for recording and reproducing the program on the flexible disk FD. One diagram,

15 is a block diagram showing an overall configuration of a content supply system;

16 is a schematic diagram showing an example of a mobile phone;

17 is a block diagram showing the configuration of a mobile telephone;

18 is a diagram illustrating an example of a system for digital broadcasting.

In order to achieve the above object, a motion vector derivation method according to the present invention is a motion vector derivation method for deriving a motion vector of a block constituting a picture, the reference for obtaining a reference motion vector for deriving a motion vector of a target block A motion parameter acquiring step, a first parameter acquiring step for acquiring a first parameter corresponding to an interval between a picture having the reference motion vector and a picture referenced by the reference motion vector, a picture including the target block, and the target A second parameter acquiring step of acquiring at least one second parameter corresponding to an interval of a picture referred to by the block, a determining step of determining whether the first parameter is within a predetermined range, and in the determining step As a result of the determination, if the first parameter is not included in the predetermined range, The reference motion vector is scaled based on a first predetermined value and the second parameter to derive a motion vector of the target block. Meanwhile, when the first parameter is included in the predetermined range, the first parameter and the And a motion vector derivation step of deriving a motion vector of the target block by scaling the reference motion vector based on a second parameter.

The motion vector derivation method according to the present invention is a motion vector derivation method for deriving a motion vector of a block constituting a picture, comprising: a reference motion vector acquisition step of acquiring a reference motion vector for deriving a motion vector of a target block; And a first parameter obtaining step of acquiring a first parameter corresponding to an interval between a picture having the reference motion vector and a picture referenced by the reference motion vector, a picture including the target block, and a picture referenced by the target block. A second parameter acquiring step of acquiring at least one second parameter corresponding to the interval of the second step; a determination step of determining whether the first parameter is equal to or greater than a first predetermined value; and a result of the determination in the determination step When the first parameter is equal to or greater than the first predetermined value, the first parameter is based on the first predetermined value and the second parameter. First, the reference motion vector is scaled to derive a motion vector of the target block. Meanwhile, when the first parameter is less than the predetermined value, the reference motion vector is scaled based on the first parameter and the second parameter. And a motion vector derivation step of deriving a motion vector of the target block.

Here, in the determining step, it is further determined whether or not the first parameter is less than or equal to a second predetermined value, which is a value smaller than the predetermined first predetermined value.In the motion vector derivation step, as a result of the determination in the determining step, If the first parameter is equal to or less than the second predetermined value, the motion vector of the target block may be derived by scaling the reference motion vector based on the second predetermined value and the second parameter.

In addition, the motion vector derivation method, with reference to a multiplier parameter table indicating the relationship between the first parameter and the value of the reciprocal of the first parameter, converts the obtained first parameter to the value of the reciprocal, Preferably, the method further includes a conversion step of acquiring the obtained value as a third parameter.

In the motion vector deriving step, the reference motion vector, the second parameter, and the third parameter are multiplied when the reference motion vector is scaled based on the first parameter and the second parameter. It is desirable to derive the motion vector of the block.

As a result, the division process required when scaling the reference motion vector can be performed by multiplication processing, and the multiplier stored in the memory by limiting the value of a parameter used when scaling the reference motion vector to a predetermined range. You can reduce the parameter table. In addition, it is possible to prevent the inconsistency of the result due to the operation error in the encoding process and the decoding process.

The motion vector derivation method according to the present invention is a motion vector derivation method for deriving a motion vector of a block constituting a picture, comprising: a reference motion vector acquisition step of acquiring a reference motion vector for deriving a motion vector of a target block; And a first parameter obtaining step of acquiring a first parameter corresponding to an interval between a picture having the reference motion vector and a picture referenced by the reference motion vector, a picture including the target block, and a picture referenced by the target block. A second parameter acquiring step of acquiring at least one second parameter corresponding to the interval of the second step; a determining step of determining whether the first parameter is equal to or greater than a first predetermined value; If the first parameter is equal to or greater than the first predetermined value, the reference motion vector is converted into the target block. Derived as a motion vector, and when the first parameter is less than the predetermined value, a motion vector derivation that derives a motion vector of the target block by scaling the reference motion vector based on the first parameter and the second parameter. Characterized in that it comprises a step.

Here, in the determining step, it is further determined whether or not the first parameter is less than or equal to a second predetermined value, which is a value smaller than the predetermined first predetermined value.In the motion vector derivation step, as a result of the determination in the determining step, If the first parameter is equal to or less than the second predetermined value, the reference motion vector may be derived as the motion vector of the target block.

This can simplify the derivation of the motion vector when the distance between the picture referenced by the reference motion vector and the picture having the reference motion vector is outside the predetermined range.

The moving picture coding method according to the present invention is a moving picture coding method for coding each picture constituting a moving picture in block units, and using the motion vector derived by the motion vector derivation method according to the present invention, the motion of a block to be encoded. And a motion compensation step of generating a compensation image, and an encoding step of encoding the encoding target block by using the motion compensation image.

The moving picture decoding method according to the present invention is a moving picture decoding method for decoding moving picture coded data in which each picture constituting a moving picture is coded in block units, using a motion vector derived by the motion vector derivation method according to the present invention. And a motion compensation step of generating a motion compensation image of the decoding object block, and a decoding step of decoding the decoding object block by using the motion compensation image.

In addition, the present invention can be realized as such a motion vector derivation method, moving picture coding method and moving picture decoding method, and includes as a means the characteristic steps included in such a motion vector deriving method, moving picture coding method and moving picture decoding method. It may be realized as a motion vector deriving apparatus, a moving picture coding apparatus, and a moving picture decoding apparatus, or as a program for causing these steps to be executed by a computer. It goes without saying that such a program can be delivered via a recording medium such as a CD-ROM or a transmission medium such as the Internet.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

(Embodiment 1)

3 is a block diagram showing a configuration of a video encoding apparatus according to the present embodiment. In the process of FIG. 3, the terms already described with reference to FIG. 1 in the prior art will be described using the same reference numerals as in FIG. 1. The present embodiment differs from the prior art in that the numerical width of the parameter used for deriving the motion vector of the picture to be encoded 1202 is limited to a predetermined range.

As shown in FIG. 3, the moving picture encoding apparatus includes a motion vector encoder 10, a motion vector derivation unit 11, a memory 12, a subtractor 13, an orthogonal transform unit 14, and a quantization unit 15. And an inverse quantizer 16, an inverse orthogonal transform unit 17, an adder 18, and a variable length encoder 19.

The motion vector encoder 10 encodes a motion vector (MV1 or the like) of each picture and outputs it as a motion vector stream. The motion vector derivation unit 11 uses the motion vectors MVtar (MV1), the parameters TRtar, and the parameters TR1 of the reference block MB2, and the motion vectors MVscl and MVb of the encoding target block MB1. And MVf). Here, the motion vector of the reference block MB2 is scaled based on Equations 1 (a) and 1 (b). The parameter TRtar corresponds to TRb or TRf already described.

The memory 12 stores the image data of the reference picture and the motion vector MVscl of the picture to be encoded 1202 derived from the motion vector derivation unit 11. In this memory 12, motion compensation data is generated based on the image data of the reference picture and the motion vector MVscl of the picture to be encoded 1202. The subtractor 13 calculates a difference between the input image data and the motion compensation data input from the memory 12 to obtain a difference value. The orthogonal transform unit 14 DCT transforms the difference value and outputs a DCT coefficient. The quantization unit 15 quantizes the DCT coefficients using a quantization step. The inverse quantization unit 16 inverse quantizes the quantized DCT coefficients using the quantization step, and returns the original DCT coefficients. The inverse orthogonal transform unit 17 inversely orthogonally transforms the DCT coefficients and outputs differential image data (differential values).

The adder 18 adds the differential image data (differential value) from the inverse orthogonal transform unit 17 and the image data of the reference picture stored in the memory 12 to input the image data of the encoding target picture 1202. Decoded image data corresponding to (original input image data) is obtained. The decoded image data is stored in the memory 12 as image data for reference at the time of encoding of the encoding target picture encoded after the encoding target picture 1202. The variable length encoder 19 performs variable length encoding on the DCT coefficients quantized by the quantizer 15.

Next, the motion at the time of encoding by the direct mode in the moving picture coding apparatus configured as described above will be described with reference to FIG.

The motion vector of each picture is encoded by the motion vector encoder 10 and output as a motion vector stream.

The motion vector derivation unit 11 derives the motion vector of the encoding target block MB1 by scaling the motion vectors MVtar and MV1 of the reference block MB2 by the parameters TRtar and TR1. The memory 12 extracts, from the image data of the stored reference picture, the image represented by the motion vector derived by the motion vector derivation unit 11 and outputs it as motion compensation data.

The subtractor 13 calculates the difference between the input image data and the motion compensation data output from the memory 12, and obtains the difference image data that is the difference value. The difference value is orthogonally transformed by the orthogonal transform unit 14 and converted into DCT coefficients. The DCT coefficients are quantized in the quantization unit 15 and inversely quantized to the original DCT coefficients in the inverse quantization unit 16 and restored. The DCT coefficients are inversely orthogonally transformed into differential image data (differential values) by the inverse orthogonal transform unit 17, and the differential image data (differential values) are added to the motions output from the memory 12 by the adder 18. The decoded image data corresponding to the original input image data is obtained by adding the compensation data. The obtained input image data is stored in the memory 12 as image data for reference at the time of encoding of the next encoding target picture.

In addition, the DCT coefficients quantized by the quantization unit 15 are variable length coded by the variable length encoding unit 19 and output as a stream.

Next, a configuration of scaling the motion vector by limiting the numerical width (size) of the parameter to a predetermined range will be described with reference to FIG.

4 is a block diagram showing the configuration of the motion vector derivation unit 11 of FIG.

As shown in Fig. 4, the motion vector derivation unit 11 includes a comparator 20, a switching unit 21, a multiplier parameter table (for multipliers) 22, multipliers 23 and 25, and a multiplier parameter table. (For dividing) 24 is provided.

The comparison unit 20 compares whether the parameter TR1 relating to the motion vector MVtar MV1 of the reference block MB2 exceeds a predetermined value. The switching unit 21 switches between selecting the maximum value of the parameter TR stored in advance or selecting the parameter TR1 according to the comparison result of the comparing unit 20. The multiplier parameter table 22 shows the correspondence between the parameter TRtar (TRb or TRf) and the multiplier (multiplication value). The multiplier 23 multiplies the multiplier parameter output from the multiplier parameter table 22 by the motion vector MVtar MV1 of the reference block MB2.

The multiplier parameter table 24 shows the correspondence between the output value of the switching unit 21 and the multiplication value. The multiplier 25 multiplies the output value of the multiplier 23 by the parameter output from the multiplier parameter table 24.

Hereinafter, the operation will be described with reference to FIG. 4. The motion vector derivation part 11A shown in FIG. 4 shows the motion vector derivation part 11 in the block diagram of the moving picture coding apparatus shown in FIG.

The parameter TR1 relating to the motion vector MVtar MV1 of the reference block MB2 is compared whether or not the predetermined value predetermined by the comparison unit 20 is exceeded. As a result, when the parameter TR1 does not exceed the predetermined value, the switching unit 21 selects the parameter TR1 as it is. On the other hand, when the parameter TR1 exceeds a predetermined value, the switching unit 21 selects a predetermined predetermined value (maximum value of TR).

The multiplier parameter corresponding to the parameter TRtar (TRb or TRf) of the motion vector MVscl (MVb or MVf) of the encoding target block is selected from the multiplier parameter table 22, and the selected multiplier parameter is multiplier 23. Is multiplied by the motion vector MVtar of the reference block MB2.

In the multiplier parameter table 24, a multiplier parameter corresponding to the parameter selected by the switching unit 21 is selected, and the selected multiplier parameter is multiplied by the multiplier 25 to the output of the multiplier 23.

In this way, the value obtained by multiplying the multiplication parameter in the multiplier 23 and the multiplier 23 by the motion vector MVtar of the reference block MB2 (scaled value) is the motion vector MVscl of the picture 1202 to be encoded. It becomes

FIG. 5 shows an example of the multiplier parameter table, which corresponds to the multiplier parameter table 24 of FIG. 4.

The leftmost column shown in FIG. 5 represents the parameter TR1 (divisor) input to this table, and this parameter TR1 is limited to a predetermined range from "1" to "8". The middle column shows the inverse of the parameter (1 / TR1). The rightmost column represents a multiplier parameter Tscl and a value approximated to the reciprocal of the parameter (1 / TR1) displayed in the middle column. In the actual calculation, since the rightmost multiplication parameter Tscl is used as a value for deriving the motion vector MVscl of the picture 1202 to be encoded, the calculation is simplified.

That is, for example, two motion vectors MVf and MVb of the encoding target block MB1 shown in FIG. 1 are calculated using the following equations (a) and (b).

MVf = MV1 x TRf x Tscl... Equation 2 (a)

MVb = -MV1 x TRb x Tscl... Equation 2 (b)

Here, MVf is a forward motion vector of the encoding target block MB1, MVb is a backward motion vector of the encoding target block MB1, and Tscl is a multiplier parameter corresponding to the inverse of the interval between the picture 1200 and the picture 1203. That is, 1 / TR1, TRf is the interval between the picture 1200 and the picture 1702, and TRb is the interval between the picture 1202 and the picture 1203.

Next, a process of obtaining the motion vector MVscl of the encoding target block MB1 will be described with reference to FIG. 6.

6 is a flowchart showing a processing procedure for obtaining a motion vector MVscl. The motion vector derivation part 11A acquires the information of the motion vector MVtar which the reference block MB2 has (step S401). This motion vector MVtar corresponds to MV1 in Expressions 1 (a) and 1 (b). Next, the motion vector derivation unit 11A obtains a parameter TRtar and a parameter TR1 for deriving the motion vector MVscl of the encoding target block MB1 (step S402). This parameter TRtar corresponds to TRf and TRb in Equations 1 (a) and 1 (b).

Next, the comparing unit 20 determines whether or not the parameter TR1 corresponding to the divisor is equal to or greater than a predetermined value (step S403). As a result of the determination, if the parameter TR1 is equal to or larger than the predetermined value, the switching unit 21 selects a parameter corresponding to the maximum divisor (the maximum value "8" of TR1 in the example of FIG. 5). Accordingly, the motion vector derivation unit 11A derives the motion vector MVscl of the encoding target block MB1 by scaling the motion vector MVtar obtained in step S401 using the parameter corresponding to the maximum divisor. (Step S405). On the other hand, if the acquired parameter TR1 is less than the predetermined value, the switching unit 21 selects a parameter corresponding to the divisor. Accordingly, the motion vector derivation unit 11A performs the same scaling using the parameter corresponding to the divisor to calculate the motion vector MVscl of the block to be encoded MB1 (step S404).

As described above, according to the present embodiment, by limiting the value of a parameter used when scaling the motion vector of the reference block to a predetermined value or less, the multiplier parameter table corresponding to the divisor stored in the memory can be reduced. In addition, there is an effect that the inconsistency of the result due to the operation error can be prevented in the encoding process and the decoding process.

In the present embodiment, the determination (step S403) determines whether the parameter TR1 is equal to or greater than a predetermined value, but is not limited to this, and it is determined whether the parameter TR1 falls within a predetermined predetermined range. You can judge. For example, when the motion vector MV1 included in the reference block MB2 refers to a picture behind, as shown in FIG. 7, a multiplier parameter corresponding to the parameter TR1 (divisor) and the parameter TR1. (Tscl) becomes a negative value as follows. In Fig. 7, the picture 1500, the picture 1501, the picture 1502, and the picture 1503 are arranged in the display order. The picture 1501 is a picture to be encoded, and the block MB1 is a block to be encoded. In FIG. 7, the bidirectional prediction of the block MB1 of the picture 1501 is performed using the picture 1500 and the picture 1503 as the reference picture.

The picture 1500 that is a reference picture in front of the picture 1501 has a motion vector that refers to the picture 1503 in the back. Therefore, the motion vector of the encoding target block MB1 is determined using the motion vector MV1 of the reference block MB2 of the picture 1500 positioned in front of the picture 1501 to be encoded. The two motion vectors MVf and MVb obtained are calculated by using Equations 2 (a) and 2 (b). In this way, when the motion vector MV1 included in the reference block MB2 refers to the picture behind, the multiplier parameter Tscl corresponding to the parameter TR1 (divisor) and the parameter TR1 becomes negative.

Therefore, it is determined whether the parameter TR1 is equal to or greater than the first predetermined value and whether the parameter TRl is equal to or less than the second predetermined value. As a result of this determination, when the parameter TR1 is equal to or larger than the first predetermined value, the motion vector MVtar is scaled using the parameter corresponding to the maximum divisor to derive the motion vector MVscl of the encoding target block MB1. . If the parameter TR1 is equal to or less than the second predetermined value, the motion vector MVtar is scaled using a parameter corresponding to the minimum divisor to derive the motion vector MVscl of the encoding target block MB1. Further, when the parameter TR1 is less than the first predetermined value and larger than the second predetermined value, the motion vector MVtar is scaled using the parameter TR1, and the motion vector MVscl of the encoding target block MB1 is scaled. To derive

In addition, although it was demonstrated also in the prior art, in this embodiment, the picture interval of the parameters TR1 and TRtar is not limited to the time interval between pictures, For example, the data and the picture using the difference of the picture number allocated to each picture are used. An index used for scaling a motion vector and recognizing temporal intervals in the display order between pictures, such as data using a difference in display order (or information indicating a display order of pictures) and data using a number of pictures between pictures. Any data may be used.

If the divisor is not limited to a predetermined range, the parameters of the multiplier corresponding to the divisor are infinite, so that the parameter table corresponding to the divisor cannot be realized and the structure itself of realizing the division by multiplication cannot be realized.

In addition, as an example of judging whether the parameter TR1 is included in a predetermined predetermined range, as illustrated in FIG. 6, it is described whether or not it is "above a predetermined value", but "over a predetermined value" or "predetermined value". Under "conditions may be sufficient.

(Embodiment 2)

In the first embodiment, when deriving the motion vector MVscl by scaling the motion vector MVtar, which is a reference motion vector, the upper limit value of the divisor of the parameter TR1 and the multiplier parameter table is compared, and TR1 is equal to or greater than the upper limit value. At this time, the value corresponding to the largest divisor of the multiplier parameter table was used as the multiplier parameter corresponding to the input parameter TR1. In the second embodiment, the upper limit value of the divisor of the parameter TR1 and the multiplier parameter table are compared, and when the TR1 is equal to or larger than the upper limit value, the motion vector MVtar is not derived by scaling, and the input MVtar is used as the motion vector MVscl. ) Thereby, the derivation process of the motion vector MVscl when it is more than an upper limit is simplified. EMBODIMENT OF THE INVENTION Hereinafter, Embodiment 2 of this invention is described, referring drawings.

8 is a block diagram showing the configuration of a motion vector derivation unit according to the second embodiment. The motion vector derivation part 11B shown in FIG. 8 has shown the motion vector derivation part 11 in the block diagram of the image coding apparatus shown in FIG. The configuration other than the motion vector derivation unit 11 in the block diagram of the picture coding apparatus shown in FIG. 3 is as described in the first embodiment. Therefore, the motion vector derivation part 11B shown in FIG. 8 is demonstrated, referring FIG. 5 and FIG.

As shown in Fig. 8, the motion vector derivation unit 11B includes a multiplier parameter table (for multipliers) 50, a multiplier parameter table (for divisors) 51, a comparator 52, and multipliers 53, 54. , And a switching unit 55 is provided.

This motion vector derivation unit 11B uses a motion vector MVtar (MV1), parameters TRtar (TRf and TRb), and parameter TR1 of the reference block MB2 shown in FIG. 1 to encode a block to be encoded. The motion vectors MVb and MVf of MB1 are derived. Here, the motion vectors MVtar of the reference block MB2 are scaled using the above-described equations 2 (a) and 2 (b). The parameter TRtar corresponds to TRb or TRf already described.

The comparing unit 52 compares whether the parameter TR1 regarding the motion vector MVtar of the reference block MB2 exceeds a predetermined value. Here, a predetermined predetermined value is "8" which is the maximum value of the divisor which the multiplier parameter table shown in FIG. 5 has, for example. The switching unit 55 selects the output (process 57) of the multiplier 54 or the motion vector MVtar (process 58) of the input reference block MB2 according to the comparison result of the comparing unit 52.

The multiplier parameter table (for multipliers) 50 indicates the correspondence between the parameter TRtar (TRb or TRf) and the multiplier (multiplication value). The multiplier parameter table (for divisor) 51 shows the correspondence between TR1 and the multiplier (divisor). In the second embodiment, the TRtar input to the multiplier parameter table 50 is input to the multiplier 53 as it is, but not limited to this, the arithmetic processing may be performed in the multiplier parameter table 50 as necessary. do.

The multiplier 53 multiplies the multiplier parameter output from the multiplier parameter table (for multipliers) 50 by the motion vector MVtar MV 1 of the reference picture 1203. The multiplier 54 multiplies the output value of the multiplier 53 by the multiplier parameter output from the multiplier parameter table (for dividing) 51. In addition, the order of the multiplication process of the multiplier 53 and the multiplier 54 may be reversed.

Next, the motion of the motion vector derivation part 11B shown in FIG. 8 is demonstrated using FIG. 9 is a flowchart showing a processing procedure for obtaining a motion vector MVscl.

First, a motion vector MVtar of the reference block MB2 is obtained (step S601). Next, the parameters TR1 and TRtar for deriving the motion vector MVscl of the encoding target block MB1 are obtained (step S602).

Next, it is determined whether or not the parameter TR1 corresponding to the acquired divisor is equal to or larger than a predetermined value (step S603). As a result of the determination, if the parameter TR1 corresponding to the divisor is a predetermined value or more, the processing 58 is selected by the switching unit 55. On the other hand, if the parameter TR1 corresponding to the divisor is not greater than or equal to the predetermined value, the processing 57 is selected by the switching unit 55.

When the processing 58 is selected by the switching unit 55, the motion vector MVTar referred to in step 601 is used as the motion vector MVscl (step S605). On the other hand, when the process 57 is selected by the switching unit 55, the motion vector MVscl is derived using the parameter corresponding to the divisor TR1 (step S604). That is, the result of the multiplication process of the multiplier 53 and the multiplier 54 becomes a motion vector MVscl.

Since the picture to be encoded 1202 shown in FIG. 1 has two motion vectors MVf and MVb before and after, the processing shown in FIG. 9 is performed for each. That is, in order to calculate the motion vector MVf as the motion vector MVscl, the parameter TRtar obtained in step S602 is the parameter TRf, and in order to calculate the motion vector MVb as the motion vector MVscl, The parameter TRtar obtained in step S602 is a parameter TRb.

As described above, according to the second embodiment, the parameter value used when scaling the motion vector of the reference block is limited to a predetermined range, and when exceeding the upper limit value, the input value is input without scaling the motion vector MVtar. By determining a certain processing order in which MVtar is used as the motion vector MVscl, it is possible to prevent the inconsistency of the result due to an operation error in the encoding process and the decoding process. In addition, the throughput for deriving a motion vector can be reduced. In addition, the multiplier parameter table stored in the memory can be reduced.

In addition, although it demonstrated also in the prior art, in this Embodiment 2, the parameters TR1 and TRtar are not limited to time data, but data using the difference of the picture number allocated to each picture (for example, the picture 1200 in FIG. 1). If the picture number of 1200 is 1200 and the picture number of the picture 1203 is 1203, 3 obtained by subtracting 1200 from 1203, data using the number of pictures between the picture to be encoded and the reference picture (for example, in FIG. As TR1, the number of pictures between the picture 1200 and the picture 1203 is two, and the picture interval is 2 + 1 = 3). Any data can be used.

In the second embodiment, multiplication processing is performed by the multiplication unit 54 using the multiplier parameter table 51 when the upper limit value of the divisor of the parameter TR1 and the multiplier parameter table are not exceeded and the TR1 does not exceed the upper limit value. 12, the dividing unit 94 may perform the division process using the divisor parameter table 91. As shown in FIG. The motion vector derivation part 11C shown in this FIG. 12 shows the motion vector derivation part 11 in the block diagram of the image coding apparatus shown in FIG. In addition, the structure other than the motion vector derivation part 11 in the block diagram of the moving picture coding apparatus shown in FIG. 3 is as having demonstrated in Embodiment 1. As shown in FIG. 12, the same code | symbol as the code | symbol used in FIG. 8 was used for the structure similar to FIG.

In the first and second embodiments described above, a case in which the motion vector shown in FIG. 1 is derived using the equations 2 (a) and 2 (b) is described. Even when a vector is derived, the invention described in the present specification can be used.

First, a method of deriving the motion vector in the direct mode shown in FIG. 10 will be described. In Fig. 10, the picture 1700, the picture 1701, the picture 1702 and the picture 1703 are arranged in the display order, and the block MB1 is a block to be encoded. In FIG. 10, an example of bidirectionally predicting the encoding target block MB1 using the picture 1700 and the picture 1703 as a reference picture is shown.

The motion vectors MVf and MVb1 of the encoding target block MB1 are represented by Equation 2 using the motion vector MV1 of the reference block MB2 located later than the encoding target block MB1 in the display time. It can be derived by (a) and equation (2).

Here, MVf is a forward motion vector of the encoding target block MB1, MVb is a backward motion vector of the encoding target block MB1, and Tscl is a multiplier parameter corresponding to the inverse of the interval between the picture 1700 and the picture 1703. That is, 1 / TR1, TRf is the interval between the picture 1701 and the picture 1702, and TRb is the interval between the picture 1702 and the picture 1703.

In addition, TR1, TRf, and TRb may be any data as long as it can quantitatively determine the picture interval as described above. The flow of processing for obtaining the motion vector MVf or the motion vector MVb is as described with reference to FIG. 6 or 9.

Next, a method of deriving the motion vector shown in FIG. 11 will be described. In Fig. 11, the picture 1800, the picture 1801 and the picture 1802 are arranged in the display order, and the block MB1 is the encoding target block. In FIG. 11, in the encoding target block MB1, a picture 1800 and a picture 1801 are predicted as a reference picture, and have a motion vector MV1 and a motion vector MV2. The motion vector MV2 is predictively encoded using the motion vector MVscl obtained by scaling the motion vector MV1 as follows.

First, the motion vector MVscl, which is a vector from the encoding target block MB1 to the picture 1800 referenced by the motion vector MV2, is derived using the following equation. In addition, it is assumed that the motion vector MV2 to be encoded is derived by a predetermined method. Equations 3 (a) and 3 (b) can be applied to the case shown in Embodiment 1, and Equations 4 (a) and 4 (b) can be applied to the case shown in Embodiment 2.

MVscl = MV1 × TR3 × Tscl (TR1 <upper limit) Equation 3 (a)

MVscl = MV1 × TR3 × TsclMin (TR1 ≥ upper limit) Equation 3 (b)

MVscl = MV1 × TR3 × Tscl (TR1 <upper limit) Equation 4 (a)

MVscl = MV1 (TR1 ≥ upper limit) Equation 4 (b)

Here, Tscl is the reciprocal of TR1 when the TR1 is the interval between the picture 1801 and the picture 1802, and the upper limit is the maximum divisor ("8" in FIG. 5) in the multiplier parameter table 51 (for dividing). , TsclMin is a multiplier parameter corresponding to the largest divisor (TR1) in the multiplier parameter table 51 (for dividing), TR3 is the interval between the picture 1800 and the picture 1802, TR1 is the picture 1801 and the picture ( 1802 intervals.

Next, in order to encode the motion vector MV2, the motion vector MVscl derived from any one of Equations 3 (a) to 4 (b) and a predetermined value are used without encoding the motion vector MV2 itself. Only the difference (difference vector) of the motion vector MV2 derived by the method is encoded, and in the decoding process, the motion vector MV2 is derived using MVscl which scales the encoded difference vector and the motion vector MV1. do.

As described above, TR1 and TR3 may be any data as long as the data can quantitatively determine the temporal interval in the inter-picture display order. The flow of processing for obtaining the motion vector MVscl is as described with reference to FIG. 6 or 9. In addition, in the multiplier parameter table shown in FIG. 5, although the upper limit is made into "8", it is not limited to this, It is good also as "16" and "32". However, if the divisor is large, the change in the reciprocal of the divisor is small. Therefore, even if the multiplier parameter created by setting the upper limit value is large, the error of the motion vector derived is very small.

(Embodiment 3)

Fig. 13 is a block diagram showing the structure of a moving picture decoding apparatus according to the present embodiment.

The moving picture decoding apparatus includes a variable length decoding unit 1000, an inverse quantization unit 1001, an inverse orthogonal transform unit 1002, an add operation unit 1003, a motion vector decoder 1004, A motion vector derivation unit 1005 and a memory 1006 are provided. In addition, since the structure and the motion of the motion vector derivation part 1005 are the same as that of Embodiment 1 and Embodiment 2, detailed description is abbreviate | omitted.

The variable length decoding unit 1000 executes a variable length decoding process on the encoded data stream output from the video encoding apparatus according to each of the above embodiments, and outputs prediction error coded data to the inverse quantization unit 1001. The motion vector derivation parameters TRtar and TR1 are output to the motion vector derivation unit 1005. The inverse quantizer 1001 inversely quantizes the input prediction error encoded data. The inverse orthogonal transform unit 1002 inversely orthogonally transforms the inverse quantized prediction error coded data, and outputs differential image data.

The motion vector decoding unit 1004 decodes the input motion vector stream and extracts information of the motion vector. The motion vector derivation unit 1005 uses the motion vector MVtar, the parameter TRtar, and the parameter TR1 of the reference block MB2 to obtain the motion vectors MVscl (MVb and MVf) of the encoding target block MB1. To derive The memory 1006 stores the image data of the reference picture and the motion vector MVscl of the encoding target block MB1 derived from the motion vector derivation unit 1005. The memory 1006 generates motion compensation data based on the image data of the reference picture and the motion vector MVscl of the encoding target block MB1. The addition calculating unit 1003 adds the input difference image data and the motion compensation data, and generates and outputs a decoded image.

Next, a description will be given of the motion when decoding by the direct mode in the moving picture decoding apparatus configured as described above.

The encoded data stream output from the video encoding apparatus is input to the variable length decoder 1000. The variable length decoder 1000 performs variable length decoding on the encoded data stream, outputs differential coded data to the inverse quantizer 1001, and simultaneously outputs the parameters TRtar and TR1 to the motion vector derivation unit 1005. Output to. The differential coded data input to the inverse quantization unit 1001 is inversely quantized and then inversely orthogonally transformed by the inverse orthogonal transformation unit 1002 and output to the add operation unit 1003 as differential image data.

The motion vector stream input to the moving picture decoding apparatus according to the present embodiment is input to the motion vector decoding unit 1004 to extract the motion vector information. Specifically, the motion vector decoding unit 1004 decodes the motion vector stream and outputs a motion vector derivation parameter MVtar to the motion vector derivation unit 1005. Subsequently, the motion vector derivation unit 1005 derives the motion vectors MVscl (MVb and MVf) of the encoding target block using the motion vectors MVtar and the parameters TRtar and TR1. The memory 1006 then extracts, from the image data of the stored reference picture, the image represented by the motion vector derived from the motion vector derivation unit 1005 and outputs it as motion compensation data. The addition calculating unit 1003 adds the input difference image data and the motion compensation data, generates decoded image data, and finally outputs it as a reproduced image.

(Embodiment 4)

In addition, a program for realizing the configuration of the moving picture coding method or the moving picture decoding method shown in each of the above embodiments is recorded on a storage medium such as a flexible disk, so that the processing shown in each of the above embodiments can be easily performed by an independent computer system. It becomes possible to carry out.

14 is an explanatory diagram of a storage medium for storing a program for realizing the video encoding method and the video decoding method of the first to third embodiments by a computer system.

Fig. 14 (b) shows the external appearance, the cross-sectional structure, and the flexible disk as seen from the front of the flexible disk, and Fig. 14 (a) shows an example of the physical format of the flexible disk as the main body of the recording medium. The flexible disk FD is built in the case F. On the surface of the disk, a plurality of tracks Tr are formed on the surface of the disk from the outer circumference to the inner circumference, and each track has 16 sectors Se in the angular direction. It is divided into Therefore, in the flexible disk which stores the said program, the moving picture coding method as the said program is recorded in the area | region allocated on the said flexible disk FD.

Fig. 14C shows a configuration for recording and reproducing the program on the flexible disk FD. When the program is recorded on the flexible disk FD, the moving picture coding method or the moving picture decoding method as the program is written from the computer system Cs via the flexible disk drive FDD. When the moving picture coding method is built in the computer system by the program in the flexible disk, the program is read out from the flexible disk by the flexible disk drive and transferred to the computer system.

In the above description, the description has been made using a flexible disk as a recording medium, but the same can be done using an optical disk. The recording medium is not limited to this, and any recording medium such as an IC card, a ROM cassette, or the like can be implemented.

Here, an application example of the video encoding method and the video decoding method shown in the above embodiment and a system using the same will be described.

15 is a block diagram showing the overall configuration of a content supply system ex100 for realizing a content delivery service. The area for providing communication service is divided into cells of desired size, and base stations ex107 to ex110 which are fixed wireless stations are provided in respective cells.

This content supply system ex100 is, for example, a computer ex111 and a PDA (personal digital) through the Internet service provider ex102 and the telephone network ex104 and the base stations ex107 to ex110 on the Internet ex101. Each device such as an assistant ex112, a camera ex113, a mobile phone ex114, a mobile phone with a camera ex115, and the like are connected.

However, the content supply system ex100 is not limited to the combination as shown in Fig. 15, and may be connected in any combination. Further, each device may be directly connected to the telephone network ex104 without passing through the base stations exl07 to ex110 which are fixed wireless stations.

The camera ex113 is a device capable of shooting video such as a digital video camera. In addition, the cellular phone may be a personal digital communications (PDC) system, a code division multiple access (CDMA) system, a wideband-code division multiple access (W-CDMA) system, a global system for mobile communications (GSM) system, Or PHS (Personal Handyphone System).

The streaming server ex103 is connected from the camera ex113 via the base station ex109 and the telephone network ex104, and live delivery based on the encoded data transmitted by the user using the camera ex113 is performed. It becomes possible. The encoding process of the photographed data may be performed by the camera ex113, or may be performed by a server or the like which performs the data transmission process. The moving picture data shot by the camera ex116 may be transmitted to the streaming server ex103 via the computer ex111. The camera ex116 is a device capable of capturing still images and moving images such as digital cameras. In this case, the encoding of the moving image data may be performed by the camera ex116 or by the computer ex111. The encoding process is performed by the LSI ex117 included in the computer ex111 or the camera ex116. Furthermore, software for moving picture coding / decoding may be mounted on any storage medium (CD-ROM, flexible disk, hard disk, etc.) that is a recording medium that can be read by a computer ex111 or the like. The moving picture data may also be transmitted from the mobile phone with the camera ex115. The moving picture data at this time is data encoded by the LSI included in the cellular phone ex115.

In the content supply system ex100, the content (for example, a video shot of music live or the like) shot by the user of the camera ex113, the camera ex116, or the like is encoded and streamed in the same manner as in the above embodiment. While transmitting to the server ex103, the streaming server ex103 streams the content data to the client that made the request. As the client, there are a computer ex111, a PDA ex112, a camera ex113, a mobile phone ex114 and the like which can decode the encoded data. In this way, the content supply system ex100 can receive and reproduce the encoded data at the client, and can receive and decode and reproduce the encoded data in real time at the client, thereby realizing personal broadcasting.

What is necessary is just to use the moving picture coding apparatus or the moving picture decoding apparatus shown in each said embodiment for the encoding and decoding of each apparatus which comprises this system.

As an example, a mobile phone will be described.

Fig. 16 is a diagram showing the cell phone ex115 using the moving picture coding method and the moving picture decoding method explained in the above embodiments. The cellular phone ex115 includes an antenna ex201 for transmitting and receiving radio waves to and from the base station ex110, a camera unit ex203 and a camera unit ex203 capable of capturing a still image and a video such as a CCD camera. A display unit ex202 such as a liquid crystal display for displaying the decoded data such as the captured image, the image received from the antenna ex201, a main body composed of a group of operation keys ex204, and audio such as a speaker for audio output. Encoded data or decoding such as an output unit ex208, an audio input unit ex205 such as a microphone for voice input, data of a captured moving image or still image, data of a received mail, data of a moving image or still image The recording medium ex207 for storing the old data and the slot ex206 for mounting the recording medium ex207 on the mobile phone ex115 are provided. The recording medium ex207 stores a flash memory device which is a kind of electrically erasable and programmable read only memory (EEPR0M), which is a nonvolatile memory that can be electrically rewritten or erased in a plastic case such as an SD card.

The mobile telephone ex115 will be described with reference to FIG. 17. The cellular phone ex115 controls the power supply unit ex310, the operation input control unit ex304, and the power control unit ex310 to the main control unit ex311 configured to collectively control each unit of the main body unit including the display unit ex202 and the operation key ex204. An image coding unit ex312, a camera interface unit ex303, an LCD (Liquid Crystal Display) control unit ex302, an image decoding unit ex309, a multiple separation unit ex308, a recording / reproducing unit ex307, a modulation / demodulation circuit unit ex306 ) And the voice processing unit ex305 are connected to each other via the synchronization bus ex313.

When the call termination and the power key are turned on by the user's operation, the power supply circuit unit ex310 activates the digital mobile phone with the camera ex115 in an operable state by supplying power to each unit from the battery pack.

The cellular phone ex115 receives the voice signal collected by the voice input unit ex205 in the voice call mode under the control of the main control unit ex311 including the CPU, ROM, RAM, and the like. Is converted into digital voice data, and the spectrum demodulation process is performed by the modulation / demodulation circuit unit ex306, and the digital analog conversion process and the frequency conversion process are performed by the transmission / reception circuit unit ex301 and then transmitted via the antenna ex201. The cellular phone ex115 amplifies the received data received by the antenna ex201 in the voice call mode, performs frequency conversion processing and analog digital conversion processing, and performs a spectrum despreading process by the demodulation circuit unit ex306. After converting the analog audio data by the processing unit ex305, this is output through the audio output unit ex208.

In addition, when the electronic mail is transmitted in the data communication mode, the text data of the electronic mail input by the operation of the operation key ex204 of the main body is sent out to the main control unit ex311 via the operation input control unit ex304. The main control unit ex311 spreads out the spectrum data by the modulation and demodulation circuit unit ex306, and transmits the digital data to the base station ex110 through the antenna ex201 after performing the digital analog conversion process and the frequency conversion process by the transmission / reception circuit unit ex301. do.

When image data is transmitted in the data communication mode, the image data shot by the camera unit ex203 is supplied to the image coding unit ex312 via the camera interface unit ex303. When the image data is not transmitted, it is also possible to display the image data shot by the camera unit ex203 directly on the display unit ex202 via the camera interface unit ex303 and the LCD control unit ex302.

The image encoding unit ex312 is a configuration including the moving image encoding apparatus described in the present invention, and is encoded by compression encoding the image data supplied from the camera unit ex203 by the encoding method used in the moving image encoding apparatus shown in the above embodiments. The image data is converted into image data and sent to the multiple separation unit ex308. At this time, the cellular phone ex115 simultaneously transmits the voices collected by the voice input unit ex205 while shooting by the camera unit ex203 as digital voice data to the multiplexing unit ex308 via the voice processing unit ex305. do.

The multiplexer ex308 multiplexes the encoded image data supplied from the image encoder ex312 and the audio data supplied from the voice processor ex305 in a predetermined manner, and modulates and demodulates the circuit demodulated circuit ex306 the resultant multiplexed data. The spectrum spreading process is performed at, and the transmission / reception circuit unit ex301 performs digital analog conversion processing and frequency conversion processing, and then transmits the data through the antenna ex201.

In the case of receiving data of a moving picture file linked to a home page or the like in the data communication mode, spectrum demodulation processing is performed by the demodulation circuit section ex306 by receiving the received data received from the base station ex110 via the antenna ex201. The multiplexed data is sent to the multiple separation unit ex308.

In order to decode the multiplexed data received through the antenna ex201, the multiplexer ex308 divides the multiplexed data into a bit stream of image data and a bit stream of audio data, and divides the synchronization bus ex313. The coded image data is supplied to the picture decoding unit ex309 via the voice data to the voice processing unit ex305.

Next, the image decoding unit ex309 is provided with the moving picture decoding apparatus described in the present invention, and generates the reproduced moving picture data by decoding the bit stream of the image data by the decoding method corresponding to the encoding method shown in the above embodiment. This is supplied to the display unit ex202 via the LCD control unit ex302, whereby, for example, moving image data included in the moving image file linked to the home page is displayed. At this time, the audio processing unit ex305 converts the audio data into analog audio data, and then supplies it to the audio output unit ex208, whereby the audio included in the moving image file linked to the home page, for example. The data is played back.

In addition, the present invention is not limited to the above-described system. Recently, digital broadcasting by satellites and terrestrial waves has been a hot topic, and as shown in FIG. Either one can be attached. Specifically, the broadcast station ex409 transmits the bit stream of the video information to the communication or broadcast satellite ex410 via radio waves. The broadcast satellite ex410 which has received this transmits a radio wave for broadcast, and receives the radio wave by an antenna ex406 of a home equipped with a satellite broadcast receiving facility, thereby receiving a television (receiver) ex401 or a set-top box (STB) ex407. Device to decode the bit stream and reproduce it. In addition, it is possible to mount the moving picture decoding apparatus shown in the above embodiment to the reproducing apparatus ex403 to read and decode the bit stream recorded on the storage medium ex402 such as a CD or DVD as a recording medium. In this case, the reproduced video signal is displayed on the monitor ex404. Also, a configuration in which a moving picture decoding apparatus is mounted in a set-top box ex407 connected to a cable ex405 for cable television or an antenna ex406 for satellite / terrestrial broadcasting, and reproduced by a television monitor ex408 is also conceivable. have. The moving picture decoding apparatus may be incorporated into the television, not in the set top box. In addition, the signal ex412 having the antenna ex411 is used to receive a signal from the satellite ex410, the base station ex107, or the like to reproduce a moving image on a display device such as a car navigation system ex413 included in the car ex412. It is also possible.

The image signal can also be coded by the moving picture coding apparatus shown in the above embodiment and recorded on the recording medium. As a specific example, there is a recorder ex420 such as a DVD recorder for recording an image signal on a DVD disk ex421 or a disk recorder for recording on a hard disk. It is also possible to record to the SD card ex422. If the recorder ex420 includes the moving picture decoding apparatus shown in the above embodiments, the picture signals recorded on the DVD disk ex421 or the SD card ex422 can be reproduced and displayed on the monitor ex408.

In addition, the structure of the car navigation | truck ex413 can consider the structure except the camera part ex203, the camera interface part ex303, and the image coding part ex312 among the structures shown, for example in FIG. It may also be considered in the computer ex111, the television (receiver) ex401 and the like.

In addition, the terminal of the mobile telephone ex114 or the like can consider three types of implementations: a transmitting terminal only with an encoder and a receiving terminal only with a decoder, in addition to a transmitting / receiving terminal having both an encoder and a decoder.

In this manner, the moving picture coding method or the moving picture decoding method shown in the above embodiments can be used for any one of the above-described apparatuses and systems, whereby the effects described in the above embodiments can be obtained.

In addition, this invention is not limited to such said embodiment, A various deformation | transformation or correction is possible without deviating from the range of this invention.

As is apparent from the above description, according to the motion vector derivation method according to the present invention, the division process required when scaling the reference motion vector can be performed by the multiplication process, so that the motion vector can be derived with a small amount of computation. In addition, by limiting the value of the parameter used when scaling the reference motion vector to a predetermined range, the multiplier parameter table stored on the memory can be reduced. Therefore, since the processing load at the time of deriving the motion vector is small, even a device with low processing capacity can be processed, and its practical value is large.

As described above, the motion vector deriving method, the moving picture coding method, and the moving picture decoding method according to the present invention encode, for example, each picture constituting an input image by using a mobile phone, a DVD device, a personal computer, and the like, and the moving picture coded data. It is useful as a method for outputting as a video data or decoding the video encoded data.

Claims (19)

In the motion vector derivation method for deriving the motion vector of the blocks constituting the picture, A reference motion vector acquiring step of acquiring a reference motion vector for deriving a motion vector of the target block; A first parameter acquiring step of acquiring a first parameter corresponding to an interval between a picture having the reference motion vector and a picture referenced by the reference motion vector; A second parameter acquiring step of acquiring at least one second parameter corresponding to an interval between a picture including the target block and a picture referenced by the target block; A determination step of determining whether the first parameter is included in a predetermined range; As a result of the determination in the determining step, when the first parameter is not included in the predetermined range, the reference motion vector is scaled based on the first predetermined value and the second parameter to determine a motion vector of the target block. And a motion vector derivation step of deriving a motion vector of the target block by scaling the reference motion vector based on the first parameter and the second parameter when the first parameter is included in the predetermined range. Motion vector derivation method comprising a. In the motion vector derivation method for deriving the motion vector of the blocks constituting the picture, A reference motion vector acquiring step of acquiring a reference motion vector for deriving a motion vector of the target block; A first parameter acquiring step of acquiring a first parameter corresponding to an interval between a picture having the reference motion vector and a picture referenced by the reference motion vector; A second parameter acquiring step of acquiring at least one second parameter corresponding to an interval between a picture including the target block and a picture referenced by the target block; A determination step of determining whether the first parameter is equal to or greater than a first predetermined value; As a result of the determination in the determining step, when the first parameter is equal to or greater than the first predetermined value, the motion vector of the target block is derived by scaling the reference motion vector based on the first predetermined value and the second parameter. And a motion vector derivation step of deriving a motion vector of the target block by scaling the reference motion vector based on the first parameter and the second parameter when the first parameter is less than the predetermined value. Motion vector derivation method, characterized in that. The method of claim 2, In the determining step, it is further determined whether or not the first parameter is equal to or less than a second predetermined value, which is a value smaller than the first predetermined value. In the motion vector deriving step, if the first parameter is equal to or less than the second predetermined value as a result of the determination in the determining step, the reference motion vector is scaled based on the second predetermined value and the second parameter. A motion vector derivation method comprising deriving a motion vector of a target block. The method according to claim 2 or 3, The method for deriving the motion vector comprises converting the obtained first parameter into the value of the inverse by referring to a multiplier parameter table indicating a relationship between the first parameter and the value of the inverse of the first parameter. And a transforming step of obtaining H as a third parameter. The method of claim 4, wherein In the motion vector derivation step, When the reference motion vector is scaled based on the first parameter and the second parameter, the motion vector of the target block is derived by multiplying the reference motion vector, the second parameter, and the third parameter. Motion vector derivation method. The method of claim 4, wherein And wherein the first predetermined value is a maximum value of a first parameter in the multiplier parameter table. The method of claim 6, In the motion vector derivation step, When scaling the reference motion vector based on the first predetermined value and the second parameter, converting the first predetermined value to the value of the reciprocal of the maximum value of the first parameter by referring to the multiplier parameter table. And multiplying the reference motion vector, the reciprocal value, and the second parameter to derive a motion vector of the target block. The method of claim 4, wherein And the second predetermined value is a minimum value of a first parameter in the multiplier parameter table. The method of claim 8, In the motion vector derivation step, When scaling the reference motion vector based on the second predetermined value and the second parameter, converting the second predetermined value to the value of the reciprocal of the minimum value of the first parameter by referring to the multiplier parameter table; And a motion vector of the target block is derived by multiplying the reference motion vector, the inverse value, and the second parameter. In the motion vector derivation method for deriving the motion vector of the blocks constituting the picture, A reference motion vector acquiring step of acquiring a reference motion vector for deriving a motion vector of the target block; A first parameter acquiring step of acquiring a first parameter corresponding to an interval between a picture having the reference motion vector and a picture referenced by the reference motion vector; A second parameter acquiring step of acquiring at least one second parameter corresponding to an interval between a picture including the target block and a picture referenced by the target block; A determination step of determining whether the first parameter is equal to or greater than a first predetermined value; As a result of the determination in the determination step, when the first parameter is equal to or greater than the first predetermined value, the reference motion vector is derived as a motion vector of the target block, while when the first parameter is less than the predetermined value, And a motion vector derivation step of deriving a motion vector of the target block by scaling the reference motion vector based on the first parameter and the second parameter. The method of claim 10, In the determining step, it is further determined whether or not the first parameter is equal to or less than a second predetermined value, which is a value smaller than the first predetermined value. In the motion vector derivation step, if the first parameter is less than or equal to the second predetermined value as a result of the determination in the determination step, the reference motion vector is derived as a motion vector of the target block. Way. The method of claim 2 or 10, The interval between the picture and the picture is a temporal interval in the display order of the picture and the picture, and a time interval between the pictures or a difference between a picture number assigned to the picture and the picture or a picture existing between the pictures. Motion vector derivation method, characterized in that the interval based on the number of sheets. In the video encoding method for encoding each picture constituting a video in block units, A motion compensation step of generating a motion compensation image of the encoding object block by using the motion vector derived by the motion vector derivation method of any one of claims 2 to 12; And an encoding step of encoding the encoding target block by using the motion compensation image. In the moving picture decoding method of decoding moving picture coded data in which each picture constituting a moving picture is coded in block units, A motion compensation step of generating a motion compensation image of the decoding object block by using the motion vector derived by the motion vector deriving method of any one of claims 2 to 12; And a decoding step of decoding the decoding object block using the motion compensation image. In the motion vector derivation device for deriving the motion vector of the block constituting the picture, Reference motion vector obtaining means for obtaining a reference motion vector for deriving a motion vector of the target block; First parameter acquiring means for acquiring a first parameter corresponding to an interval between a picture having the reference motion vector and a picture referenced by the reference motion vector; Second parameter acquiring means for acquiring at least one second parameter corresponding to an interval between a picture including the target block and a picture referred to by the target block; Determination means for determining whether the first parameter is equal to or greater than a first predetermined value; As a result of the determination by the determining means, when the first parameter is equal to or greater than the first predetermined value, the motion vector of the target block is derived by scaling the reference motion vector based on the first predetermined value and the second parameter. And a motion vector derivation means for deriving a motion vector of the target block by scaling the reference motion vector based on the first parameter and the second parameter when the first parameter is less than the predetermined value. Motion vector derivation device, characterized in that. In the motion vector derivation device for deriving the motion vector of the block constituting the picture, Reference motion vector obtaining means for obtaining a reference motion vector for deriving a motion vector of the target block; First parameter acquiring means for acquiring a first parameter corresponding to an interval between a picture having the reference motion vector and a picture referenced by the reference motion vector; Second parameter acquiring means for acquiring at least one second parameter corresponding to an interval between a picture including the target block and a picture referred to by the target block; Determination means for determining whether the first parameter is equal to or greater than a first predetermined value; As a result of the determination by the determining means, when the first parameter is equal to or greater than the first predetermined value, the reference motion vector is derived as a motion vector of the target block, while when the first parameter is less than the predetermined value, And a motion vector derivation means for deriving a motion vector of the target block by scaling the reference motion vector based on the first parameter and the second parameter. In the moving picture encoding apparatus for encoding each picture constituting the moving picture in block units, Motion compensation means for generating a motion compensation image of the encoding object block by using the motion vector derived by the motion vector derivation method of any one of claims 2 to 12; And encoding means for encoding the encoding object block by using the motion compensation image. In a moving picture decoding apparatus for decoding moving picture coded data in which each picture constituting a moving picture is coded in block units, Motion compensation means for generating a motion compensation image of the decoding object block by using the motion vector derived by the motion vector deriving method of any one of claims 2 to 12; And decoding means for decoding the decoding object block by using the motion compensation image. In the program for deriving the motion vector of the blocks constituting the picture, A program comprising causing a computer to perform the steps included in the method for deriving the motion vector of claim 2.